Processing method of fresh and mellow green tea

Abstract

A processing method of fresh and mellow green tea comprises the following steps: 1, selecting raw materials; 2, spreading: putting the tea leaves into a spreading machine, and spreading the tea leaves in a yellow light warm air and dark cold air composite alternate spreading mode; 3, performing fixation: performing fixation on the spread tea leaves in a roller-steam combined fixation mode, and collecting water vapor generated by fixation at the same time; 4, spreading for cooling for the first time; performing low-temperature humidity-control variable-speed spreading and cooling treatment on the tea leaves subjected to fixation; 5, rolling: carrying out low-temperature humidity-controlled frequency-controlled variable-pressure rolling on the tea leaves subjected to primary spreading and airing; 6, performing gross fire: performing variable-temperature short-time stir-frying on the rolled tea leaves, and performing gross fire; 7, secondary spreading and cooling: carrying out low-temperature humidity-controlled spreading and cooling treatment on the tea leaves subjected to gross firing; according to the processing method disclosed by the invention, a processing mode of combining roller-steam combined fixation, low-temperature humidity-controlled variable-speed spreading and cooling treatment, a low-temperature rolling technology, low-temperature humidity-controlled spreading and cooling treatment and variable-temperature short-time stir-frying gross fire treatment is adopted, so that fresh and mellow green tea is stably obtained.

Description

Technical Field

[0001] The invention relates to the field of green tea processing, in particular to a method for processing fresh green tea. Background Art

[0002] Tea is the second most consumed beverage in the world after water. Green tea is very popular among consumers due to its unique quality of "clear soup and green leaves" and its antibacterial, antioxidant, and anti-cancer health benefits. Its output occupies a leading position in my country's total tea output. Currently, the consumption and output of green tea are both showing a steady growth trend, and green tea processing technology is also constantly innovating to meet consumers' diversified demands for product flavors.

[0003] Taste is the core of tea quality, including bitter, astringent, fresh, sweet and sweet taste characteristics, which determine the quality and market value of green tea. The taste quality characteristics of high-quality green tea are fresh, mellow, refreshing, etc., while poor taste is astringent, green, dull, etc. The formation of green tea taste quality is affected by fresh tea leaves and processing technology. Among them, fresh leaves are the basis for the formation of tea taste quality, and processing technology plays a key role in the formation of green tea taste by affecting the material transformation during the processing process.

[0004] Traditional green tea processing mainly involves spreading, killing, rolling and drying. During the processing, many companies often fail to spread, kill and roll enough in order to save costs, and ignore the connection processes such as cooling and rehydration, which leads to the green tea having a raw and astringent taste. During drying, the tea often has a burnt taste, a stuffy taste and a high fire due to poor equipment stability and improper parameter settings. In addition, the quality of green tea products is unstable, and the characteristic flavor is not obvious, which affects the market performance and consumer satisfaction of green tea and restricts the high-quality development of the green tea industry.

[0005] At present, the improvement of green tea quality in my country mainly focuses on the research of aroma quality such as floral green tea and chestnut green tea. There is less research on the fresh and mellow taste quality of green tea, and there is a lack of technology to stably obtain distinctive fresh and mellow green tea products. Therefore, it is very necessary to propose a processing method for fresh and mellow green tea. Summary of the invention

[0006] The object of the present invention is to provide a method for processing fresh and mellow green tea, which can stably obtain fresh and mellow green tea, so as to solve the existing technical defects and unattainable technical requirements.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for processing fresh green tea, comprising:

[0008] 1. Selection of raw materials

[0009] 1.1) Selection of tea varieties;

[0010] 1.2) Selection of tea leaves;

[0011] 2. Spreading: Place the tea leaves in the spreading machine with a thickness of 3cm-5cm, and spread them in a compound alternating spreading method of "yellow light warm wind + dark light cold wind" until the moisture content of the tea leaves reaches 68%-72%;

[0012] 3. Fixing: The tea leaves are fixed with a drum-steam combination until the moisture content of the tea leaves is 54% to 56%, and the water vapor generated by the fixing is collected at the same time;

[0013] 4. Cooling once: subject the tea leaves to low-temperature, humidity-controlled and variable-speed cooling for 20 to 30 minutes.

[0014] 5. Rolling: The tea leaves after being spread out for airing are rolled at low temperature, humidity controlled, frequency controlled and variable pressure, wherein the temperature of the rolling environment is controlled at 15-20°C and the relative humidity is 60-65%;

[0015] 6. Rough fire: the rolled tea leaves are stir-fried for a short time at a variable temperature until the moisture content of the tea leaves is about 24% to 26%;

[0016] 7. Second cooling: cool the tea leaves after rough roasting at low temperature and humidity control for 10 to 20 minutes;

[0017] 8. Full firing: After the second cooling, the tea leaves are subjected to low-humidity temperature-changing full firing until the moisture content of the tea leaves is less than 7%.

[0018] Preferably, in step 1.1), small and medium-leaf tea varieties suitable for making green tea are selected as raw material tea trees, including small and medium-leaf tea varieties such as Jiukeng, Longjing 43, Zhenong 118 and Huangjincha No. 1.

[0019] Preferably, in step 1.2), fresh tea leaves are picked from raw tea trees as raw materials, and the picking time is from mid-March to early May. The tenderness of the fresh tea leaves is: 1 bud and 1 leaf just beginning to unfold or 1 bud and 1 leaf to 1 bud and 2 leaves just beginning to unfold;

[0020] The amino acid content of the fresh tea leaves is in the range of 3.0 wt% to 6.4 wt%, and the tea polyphenol content is in the range of 18 wt% to 25 wt%.

[0021] Preferably, in step 2, the compound alternating spreading method of "yellow light warm air + dark light cold air" is:

[0022] 2.1) First, place the product under yellow light with an intensity of 5000-7000 lux and hot air with a temperature of 28-30°C for 0.5-1h;

[0023] 2.2) Turn off the yellow light source and switch to cold air with a temperature of 15-20℃ for 0.5-1h;

[0024] 2.3) The processing steps in step 2.1) and step 2.2) are performed alternately.

[0025] Preferably, in step 3, the drum-steam fixing combined treatment is performed as follows:

[0026] 3.1) The tea leaves are rolled to remove green leaves at a temperature of 220-240°C and a rotation speed of 20 r / min for 2-2.5 min.

[0027] 3.2) Steam sterilization is carried out at a temperature of 130-140°C for 0.5-1 min.

[0028] Preferably, in the step 4, the conditions for the low-temperature, humidity-controlled, variable-speed cooling treatment are as follows: the thickness of the tea leaves after withering is 2 to 3 cm, the ambient temperature is 10 to 15°C, the relative humidity of the environment is controlled to be 65 to 70% by adding the water vapor generated during the withering in step 3, the wind speed is 0.2 to 0.4 m / s, the temperature conditions follow the principle of "low first, then high", and the wind speed conditions follow the principle of "large first, then small".

[0029] In the present application, it needs to be further explained that in step 4, the cooling time of 20 to 30 minutes refers to the overall cooling time in step 4.

[0030] Preferably, in the step five, the low-temperature, humidity-controlled, frequency-controlled, and variable-pressure kneading conditions are as follows: the temperature of the kneading environment is controlled to be 15-20°C, the relative humidity of the environment is controlled to be 60-65% by adding the water vapor generated during the fixing in step three, the frequency of the kneading machine is 46r / min-52r / min, first knead with air pressure for 5-10 minutes, then knead with medium pressure for 2-4 minutes, and finally knead with air pressure for 5-10 minutes.

[0031] Preferably, the method of changing the temperature and short-time stir-frying in step 6 is:

[0032] 6.1) Dry the tea leaves after withering for 3-4 minutes at a hot air temperature of 90-110°C and a leaf thickness of 2-3 cm;

[0033] 6.2) Adjust the hot air temperature to 85-95°C and stir-fry the tea leaves for 4-5 minutes.

[0034] Preferably, in step seven, the low-temperature humidity-controlled cooling treatment conditions are: the ambient temperature is 10-15°C, the relative humidity of the environment is controlled to be 60-65% by adding water vapor generated by the withering, the tea leaves are spread to a thickness of 2-3 cm, and the drying time is 10-20 min.

[0035] Preferably, in step eight, the content of the low humidity temperature change sufficient fire is:

[0036] 8.1) Dry the tea leaves after the second cooling for 10 to 12 minutes at an ambient humidity of about 30% and a hot air temperature of 85 to 90°C;

[0037] 8.2) Adjust the hot air temperature to 75-85°C and dry for 15-18 minutes.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. This application adopts the composite alternating spreading technology of "yellow light warm wind + lightless cold wind". Through the alternating effects of different light qualities and temperatures, it promotes the biosynthesis of protein hydrolases, theanine and glutamate, laying the foundation for the formation of fresh and mellow quality tea.

[0040] 2. The present application adopts a drum-steam combined withering method, which promotes the oxidative degradation of bitter and astringent substances such as myricetin-3-O-galactoside, rutin and caffeine through a combination of dynamic and static withering methods, effectively reduces the content of bitter amino acids in tea leaves, and increases the content of umami and sweet amino acids in tea leaves. In addition, this treatment is beneficial to the dissipation of the grassy smell in the tea leaves while ensuring the color of green tea.

[0041] 3. The present application adopts a low-temperature, humidity-controlled, variable-speed cooling process. Different wind speeds can change the distribution of water in the tea leaves, improve the flexibility of the tea leaves, and reduce the overflow of tea juice during the rolling process. At the same time, low temperature stress can promote the accumulation of amino acids in the tea leaves and effectively reduce the oxidation of polyphenols in the tea leaves. In addition, the beneficial ingredients in the water vapor generated by withering are attached to the tea leaves again during the cooling process, which is beneficial to enrich the quality of the tea leaves.

[0042] 4. The present application adopts low-temperature rolling technology, and combines it with the humidity-controlled frequency-variable rolling method. By lowering the temperature of the rolling environment, controlling the rolling frequency, adding the water vapor produced by withering, and the "air-in-air" rolling method, it can effectively reduce the enzymatic oxidation of polyphenols in tea, promote the anabolism of umami and sweet amino acids, and reduce the phenol-ammonia ratio, thereby improving the umami flavor of tea while ensuring the concentration of tea flavor.

[0043] 5. The present application adopts a low-temperature controlled humidity cooling treatment method, which effectively reduces the oxidation of polyphenols and the accumulation of amino acids in tea, promotes the formation of refreshing and mellow taste qualities, and enriches the taste of tea.

[0044] 6. The present application adopts variable temperature and short-time stir-frying treatment. By combining high-then-low temperature drying with stir-frying technology, it promotes the uniform loss of water, avoids the oxidation of polyphenols and the production of watery odor caused by high temperature and high humidity during stacking, is beneficial to the full transformation of the substances contained in the tea, ensures the formation of the fragrant aroma quality of the tea, and can also promote the accumulation of amino acids and soluble sugars in the tea. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is the overall logic schematic diagram of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the attached embodiment of the present invention Figure 1 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] See also Figure 1 , embodiments of the present invention:

[0048] Embodiment 1:

[0049] like Figure 1 A method for processing fresh green tea, comprising:

[0050] 1. Selection of raw materials

[0051] 1.1) Selection of tea varieties: The tea variety selected in this embodiment is Jiukeng

[0052] 1.2) Selection of tea leaves: fresh tea leaves are picked from tea trees as raw materials. The picking time is mid-March. The tenderness of the fresh tea leaves is: 1 bud and 1 leaf just beginning to unfold. The amino acid content of the fresh tea leaves is 3.0wt%, and the content of tea polyphenols is in the range of 18.6wt%.

[0053] 2. Spreading: Place the tea leaves in the spreading machine and spread them at a thickness of 3cm. Control the ambient humidity to 55%. Use the "yellow light warm wind + dark light cold wind" compound alternating spreading method.

[0054] 2.1) First, place the product under the conditions of 5000 lux yellow light and 30°C hot air for 0.5h;

[0055] 2.2) Turn off the yellow light source and switch to cold air at 15℃ for 1 hour;

[0056] 2.3) Alternating the processing steps in step 2.1) and step 2.2) to fully promote the hydrolysis of protein and the biosynthesis of theanine and glutamic acid, and spreading the tea leaves until the moisture content of the leaves reaches 68%;

[0057] 3. Fixing: The tea leaves are fixed with a drum-steam combination to fully promote the degradation of bitter and astringent substances and the formation of umami and sweet substances. Specifically:

[0058] 3.1) The tea leaves are rolled to remove green leaves at a temperature of 220°C and a rotation speed of 20 r / min for 2.5 min.

[0059] 3.2) Steam sterilization is carried out at a temperature of 140°C for 1 minute.

[0060] 3.3) Fix the tea leaves until the moisture content is 55%, and collect the water vapor generated by the fixation;

[0061] 4. Cooling once: Cool the tea leaves at low temperature, humidity control and variable speed to promote the accumulation of theanine, glutamic acid and other umami substances, and at the same time promote the softening of the tea leaves, which is convenient for shaping;

[0062] Among them, the conditions for low-temperature, humidity-controlled and variable-speed cooling treatment are: the thickness of the tea leaves after withering is 2 cm, the ambient temperature is 10°C, the relative humidity of the environment is controlled to be 70% by adding the water vapor generated during the withering in step 3, the wind speed is 0.4 m / s, first cool for 20 minutes, then control the temperature to 15°C, the relative humidity to 65%, the wind speed to 0.2 m / s, and then cool for 10 minutes. The temperature conditions follow the principle of "low first, then high", and the wind speed conditions follow the principle of "large first, then small".

[0063] In this embodiment, it should be additionally explained that the cooling time in step 4 is 30 minutes, which is the sum of the first cooling time of 20 minutes and the second cooling time of 10 minutes.

[0064] 5. Rolling: The tea leaves after being spread out for airing are subjected to low-temperature, humidity-controlled, frequency-controlled, and variable-pressure rolling, which effectively reduces the enzymatic oxidation of polyphenols and promotes the anabolism of umami and sweet amino acids. Specifically, the conditions for low-temperature, humidity-controlled, frequency-controlled, and variable-pressure rolling are as follows: the temperature of the rolling environment is controlled at 15°C, the relative humidity of the environment is controlled at 60% by adding the water vapor generated during the withering in step 3, the frequency of the rolling machine is 52r / min, and the tea leaves are first rolled with air pressure for 10 minutes, then rolled with medium pressure for 4 minutes, and finally rolled with air pressure for 5 minutes.

[0065] 6. Raw fire: Stir-fry the rolled tea leaves for a short time at a variable temperature.

[0066] 6.1) Dry the tea leaves after withering for 4 minutes at a hot air temperature of 90°C and a leaf thickness of 2 cm;

[0067] 6.2) Adjust the hot air temperature to 95°C and stir-fry the tea leaves for 5 minutes;

[0068] 6.3) The moisture content of tea leaves after being roasted is 26%;

[0069] 7. Secondary cooling: subject the tea leaves after rough firing to low-temperature controlled humidity cooling treatment, wherein the low-temperature controlled humidity cooling treatment conditions are: the ambient temperature is 10°C, the relative humidity of the environment is controlled to be 60% by adding water vapor produced by withering, the tea leaves are spread to a thickness of 2 cm, and the drying time is 10 minutes.

[0070] 8. Full Fire: After the second cooling, heat the tea leaves at low humidity and variable temperature:

[0071] 8.1) Dry the tea leaves after secondary cooling for 12 minutes at an ambient humidity of 30% and a hot air temperature of 85°C;

[0072] 8.2) Adjust the hot air temperature to 75℃ and dry for 15 minutes.

[0073] 8.3) Heat the tea leaves until the moisture content is less than 7%.

[0074] Embodiment 2:

[0075] A method for processing fresh green tea, comprising:

[0076] 1. Selection of raw materials

[0077] 1.1) Selection of tea varieties: The tea variety selected in this embodiment is Golden Tea No. 1;

[0078] 1.2) Selection of tea leaves: fresh tea leaves picked from raw tea trees are used as raw materials. The picking time is early May. The tenderness of the fresh tea leaves is: 1 bud 1 leaf to 1 bud 2 leaves just beginning to unfold. The amino acid content of the fresh tea leaves is 6.4wt%, and the content of tea polyphenols is 20.5wt%.

[0079] 2. Spreading: Place the tea leaves in the spreading machine and spread them with a thickness of 4cm. Use the "yellow light warm wind + dark light cold wind" compound alternating spreading method:

[0080] 2.1) First, place the product under yellow light with an intensity of 7000 lux and hot air at a temperature of 28°C for 1 hour;

[0081] 2.2) Turn off the yellow light source and switch to cold air at 20℃ for 0.5h;

[0082] 2.3) Alternating the processing steps in step 2.1) and step 2.2) to fully promote the hydrolysis of protein and the biosynthesis of theanine and glutamic acid, and spreading the tea leaves until the moisture content of the leaves reaches 72%;

[0083] 3. Fixing: The tea leaves are fixed with a drum-steam combination to fully promote the degradation of bitter and astringent substances and the formation of fresh and sweet substances.

[0084] 3.1) The tea leaves are rolled to remove green leaves at a temperature of 240°C and a rotation speed of 20 r / min for 2 minutes.

[0085] 3.2) Steam sterilization is carried out at a temperature of 130°C for 0.5 min.

[0086] 3.3) Fixing the tea leaves until the moisture content is 56%, and collecting the water vapor generated by the fixing;

[0087] 4. Cool once; subject the withered tea leaves to a low-temperature, humidity-controlled, and variable-speed cooling treatment to promote the accumulation of umami substances such as theanine and glutamic acid, and to promote the softening of the tea leaves for easier shaping. The conditions for the low-temperature, humidity-controlled, and variable-speed cooling treatment are as follows: the withered tea leaves are spread out at a thickness of 3 cm, the ambient temperature is 10°C, the relative humidity of the environment is controlled to be 68% by adding the water vapor generated during the withering in step 3, the wind speed is 0.3 m / s, the tea leaves are cooled for 15 minutes, the temperature is then controlled to be 15°C, the relative humidity is 65%, the wind speed is 0.2 m / s, and the tea leaves are cooled for another 10 minutes. The temperature conditions follow the principle of "low first, then high", and the wind speed conditions follow the principle of "large first, then small".

[0088] 5. Rolling: The tea leaves after being spread out for airing are subjected to low-temperature, humidity-controlled, frequency-controlled, and variable-pressure rolling, which effectively reduces the enzymatic oxidation of polyphenols and promotes the anabolism of umami and sweet amino acids. Specifically, the conditions for low-temperature, humidity-controlled, frequency-controlled, and variable-pressure rolling are as follows: the temperature of the rolling environment is controlled at 20°C, the relative humidity of the environment is controlled at 65% by adding the water vapor generated during the withering in step 3, the frequency of the rolling machine is 46r / min, and the tea leaves are first rolled with air pressure for 5 minutes, then rolled with medium pressure for 3 minutes, and finally rolled with air pressure for 10 minutes.

[0089] 6. Raw fire: Stir-fry the rolled tea leaves for a short time at a variable temperature.

[0090] 6.1) Dry the tea leaves after withering for 3 minutes at a hot air temperature of 110°C and a leaf thickness of 3 cm;

[0091] 6.2) Adjust the hot air temperature to 85°C and stir-fry the tea leaves for 4 minutes;

[0092] 6.3) The moisture content of tea leaves after being roasted is 24%;

[0093] 7. Secondary cooling: subject the tea leaves after rough firing to low-temperature controlled humidity cooling for 10 to 20 minutes, wherein the low-temperature controlled humidity cooling treatment conditions are: the ambient temperature is 15°C, the relative humidity of the environment is controlled to be 65% by adding water vapor produced by withering, the tea leaves are spread to a thickness of 3 cm, and the drying time is 20 minutes.

[0094] 8. Full Fire: After the second cooling, heat the tea leaves at low humidity and variable temperature:

[0095] 8.1) Dry the tea leaves after secondary cooling at an ambient humidity of 30% and a hot air temperature of 90°C for 10 minutes;

[0096] 8.2) Adjust the hot air temperature to 85°C and dry for 18 minutes.

[0097] 8.3) Heat the tea leaves until the moisture content is less than 7%.

[0098] Embodiment 3:

[0099] A method for processing fresh green tea, comprising:

[0100] 1. Selection of raw materials

[0101] 1.1) Selection of tea variety: The tea variety selected in this embodiment is Zhe Nong 118;

[0102] 1.2) Selection of tea leaves: fresh tea leaves from raw tea trees are used as raw materials. The tea leaves are picked in late April. The tenderness of the fresh tea leaves is: 1 bud 1 leaf to 1 bud 2 leaves just beginning to unfold. The amino acid content of the fresh tea leaves is 3.5wt%, and the content of tea polyphenols is 24.0wt%.

[0103] 2. Spreading: Place the tea leaves in the spreading machine and spread them with a thickness of 5cm. Use the "yellow light warm wind + dark light cold wind" compound alternating spreading method:

[0104] 2.1) First, place the product under the conditions of 6000 lux yellow light and 29°C hot air for 0.8h;

[0105] 2.2) Turn off the yellow light source and switch to cold air at 18°C ​​for 0.8h;

[0106] 2.3) Alternating the processing steps in step 2.1) and step 2.2) to fully promote the hydrolysis of protein and the biosynthesis of theanine and glutamic acid, and spreading the tea leaves until the moisture content of the leaves reaches 68% to 72%;

[0107] 3. Fixing: The tea leaves are fixed with a drum-steam combination to fully promote the degradation of bitter and astringent substances and the formation of fresh and sweet substances.

[0108] 3.1) The tea leaves were rolled and sterilized at a temperature of 230°C and a rotation speed of 20 r / min for 2.2 min.

[0109] 3.2) Steam sterilization is carried out at a temperature of 135°C for 0.8 min.

[0110] 3.3) Fix the tea leaves until the moisture content is 54%, and collect the water vapor generated by the fixation;

[0111] 4. Cool once; subject the tea leaves after withering to low-temperature, humidity-controlled, and variable-speed cooling treatment; promote the accumulation of umami substances such as theanine and glutamic acid, and at the same time promote the softening of the tea leaves to facilitate shaping, wherein the conditions for the low-temperature, humidity-controlled, and variable-speed cooling treatment are as follows: the tea leaves after withering are spread out with a thickness of 2.5 cm, the ambient temperature is 12°C, the relative humidity of the environment is controlled to be 70% by adding the water vapor generated during withering in step 3, the wind speed is 0.35 m / s, the tea leaves are cooled for 12 minutes, and then the temperature is controlled to be 15°C, the relative humidity is 65%, the wind speed is 0.25 m / s, and then the tea leaves are cooled for 10 minutes. The temperature conditions follow the principle of "low first, then high", and the wind speed conditions follow the principle of "large first, then small".

[0112] 5. Rolling: The tea leaves after being spread out for airing are subjected to low-temperature, humidity-controlled, frequency-controlled, and variable-pressure rolling, which effectively reduces the enzymatic oxidation of polyphenols and promotes the anabolism of umami and sweet amino acids. Specifically, the conditions for low-temperature, humidity-controlled, frequency-controlled, and variable-pressure rolling are as follows: the temperature of the rolling environment is controlled at 18°C, the relative humidity of the environment is controlled at 62% by adding the water vapor generated during the withering in step 3, the frequency of the rolling machine is 50r / min, and the tea leaves are first rolled with air pressure for 6 minutes, then rolled with medium pressure for 4 minutes, and finally rolled with air pressure for 8 minutes.

[0113] 6. Raw fire: Stir-fry the rolled tea leaves for a short time at a variable temperature.

[0114] 6.1) Dry the tea leaves after withering for 3.5 minutes at a hot air temperature of 100°C and a leaf thickness of 2.5 cm;

[0115] 6.2) Adjust the hot air temperature to 90°C and stir-fry the tea leaves for 4.5 minutes;

[0116] 6.3) The moisture content of tea leaves after being roasted is about 25%;

[0117] 7. Secondary cooling: subject the tea leaves after rough firing to low-temperature controlled humidity cooling treatment, wherein the low-temperature controlled humidity cooling treatment conditions are: the ambient temperature is 12°C, the relative humidity of the environment is controlled to be 62% by adding water vapor produced by withering, the tea leaves are spread to a thickness of 2.5 cm, and the drying time is 15 minutes.

[0118] 8. Full Fire: After the second cooling, heat the tea leaves at low humidity and variable temperature:

[0119] 8.1) Dry the tea leaves after secondary cooling for 12 minutes at an ambient humidity of about 30% and a hot air temperature of 88°C;

[0120] 8.2) Adjust the hot air temperature to 80°C and dry for 16 minutes.

[0121] 8.3) Heat the tea leaves until the moisture content is less than 7%.

[0122] Comparative Example 1:

[0123] In this comparative example, the traditional green tea process 1 is used for processing, and the specific contents include:

[0124] 1. Raw materials: Picked from the middle of March when the tenderness of one bud and one leaf is just beginning to unfold.

[0125] 2. Spreading: Place the tea leaves on the floor of the workshop and spread them naturally. The thickness of the tea leaves is 2cm. Spread until the moisture content of the tea leaves reaches 68%.

[0126] 3. Fixing: Place the tea leaves in the drum for fixing. The temperature during fixing is 250℃ and the fixing time is 2.0min. Fix the tea leaves until the moisture content is 50%.

[0127] 4. Rolling: Rolling in a rolling machine under indoor natural environment, the rolling time is 25 minutes;

[0128] 5. Drying: Stir-fry the tea leaves at a temperature of 225°C for 1.75 minutes until the moisture content of the tea leaves reaches 27%.

[0129] 6. Full firing: Box-type full firing, full firing temperature is 85℃, full firing time is 37min, full firing until the tea leaves are dry;

[0130] Comparative Example 2:

[0131] In this comparative example, traditional black tea process 2 is used for tea processing, and the specific contents include:

[0132] 1. Raw materials: Zhejiang Nong 118, which is picked in late April with a tenderness of 1 bud and 1 leaf to 1 bud and 2 leaves just beginning to unfold.

[0133] 2. Spreading: Place the tea leaves in the spreading tank for withering, with a thickness of 5 cm, a temperature of 25°C, and a humidity of 70% until the moisture content of the tea leaves reaches 65%;

[0134] 3. Fixing the tea leaves: Place the tea leaves in the drum to fix the tea leaves. The temperature is 260℃ and the duration is 2.5min. The tea leaves are fixed until the moisture content is 45%.

[0135] 4. Rolling: Rolling in a rolling machine under indoor natural environment for 20 minutes;

[0136] 5. Drying, box-type rough burning, the rough burning temperature is 105℃, the tea pile thickness is 2cm, and the moisture content of the tea leaves after rough burning is 22%.

[0137] 6. Full firing: Box-type full firing, the temperature of full firing is 90℃, the thickness of tea leaves is 3cm, and the full firing is carried out until the tea leaves are fully dry;

[0138] The tea leaves prepared in Example 1 to Example 3, as well as the tea leaves prepared in Comparative Example 1 and Comparative Example 2 were subjected to sensory evaluation, and the results are shown in Table 1. From Table 1, it can be seen that the green tea samples prepared by the process of the present application have a green and uniform appearance, a bright green soup color, a fresh and mellow taste, a lasting fragrance, and a significantly higher quality than the green tea samples prepared by the traditional process.

[0139] Table 1 Sensory evaluation results of green tea samples treated with different processing techniques

[0140]

[0141]

[0142] From the sensory evaluation results, it can be seen that the products processed by the new process technology of this application are better than those processed by the traditional process in appearance, taste, aroma, soup color, etc., and the new process can obtain a stable and obvious fresh and mellow taste.

[0143] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0144] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that those skilled in the art can understand.

Claims

1. A method for processing fresh green tea, characterized in that: include:

1. Selection of raw materials 1.1) Selection of tea varieties; 1.2) Selection of tea leaves; 2. Spreading: Place the tea leaves in the spreading machine with a thickness of 3cm-5cm, and spread them in a compound alternating spreading method of "yellow light warm wind + dark light cold wind" until the moisture content of the tea leaves is 68%-72%; 3. Fixing: The tea leaves are fixed with a drum-steam combination until the moisture content of the tea leaves is 54% to 56%, and the water vapor generated by the fixing is collected at the same time; 4. Cooling once: subject the tea leaves to low-temperature, humidity-controlled and variable-speed cooling for 20 to 30 minutes.

5. Rolling: The tea leaves after being spread out for airing are rolled at low temperature, humidity controlled, frequency controlled and variable pressure, wherein the temperature of the rolling environment is controlled at 15-20°C and the relative humidity is 60-65%; 6. Rough fire: the rolled tea leaves are stir-fried for a short time at a variable temperature until the moisture content of the tea leaves is about 24% to 26%; 7. Second cooling: cool the tea leaves after rough roasting at low temperature and humidity control for 10 to 20 minutes; 8. Full firing: After the second cooling, the tea leaves are subjected to low-humidity temperature-changing full firing until the moisture content of the tea leaves is less than 7%.

2. The method for processing fresh green tea according to claim 1, characterized in that: In the step 1.1), small and medium leaf tea tree varieties suitable for making green tea are selected as raw material tea trees, including small and medium leaf tea tree varieties such as Jiukeng, Longjing 43, Zhenong 118 and Huangjincha No.

1.

3. The method for processing fresh green tea according to claim 2, characterized in that: In the step 1.2), fresh tea leaves are picked from raw tea trees as raw materials, and the tenderness of the fresh tea leaves is: 1 bud and 1 leaf just beginning to unfold or 1 bud and 1 leaf to 1 bud and 2 leaves just beginning to unfold; The amino acid content of the fresh tea leaves is in the range of 3.0 wt% to 6.4 wt%, and the tea polyphenol content is in the range of 18 wt% to 25 wt%.

4. The method for processing fresh green tea according to claim 1, characterized in that: In the step 2, The method of compound alternating spreading of "yellow light warm wind + dark light cold wind" is: 2.1) First, place the product under yellow light with an intensity of 5000-7000 lux and hot air with a temperature of 28-30°C for 0.5-1h; 2.2) Turn off the yellow light source and switch to cold air with a temperature of 15-20℃ for 0.5-1h; 2.3) The processing steps in step 2.1) and step 2.2) are performed alternately.

5. The method for processing fresh green tea according to claim 1, characterized in that: In step 3, the drum-steam fixing combined treatment is as follows: 3.1) The tea leaves are rolled to remove green leaves at a temperature of 220-240°C and a rotation speed of 20 r / min for 2-2.5 min. 3.2) Steam sterilization is carried out at a temperature of 130-140°C for 0.5-1min.

6. The method for processing fresh green tea according to claim 1, characterized in that: In the step 4, the conditions for the low-temperature, humidity-controlled, variable-speed cooling treatment are as follows: the thickness of the tea leaves after withering is 2 to 3 cm, the ambient temperature is 10 to 15°C, the relative humidity of the environment is controlled to be 65 to 70% by adding the water vapor generated during the withering in step 3, the wind speed is 0.2 to 0.4 m / s, the temperature conditions follow the principle of "low first, then high", and the wind speed conditions follow the principle of "large first, then small".

7. The method for processing fresh green tea according to claim 1, characterized in that: In the step 5, the low-temperature, humidity-controlled, frequency-controlled, and variable-pressure kneading conditions are as follows: the temperature of the kneading environment is controlled to be 15-20°C, the relative humidity of the environment is controlled to be 60-65% by adding the water vapor generated during the fixing in step 3, the frequency of the kneading machine is 46r / min-52r / min, first kneading with air pressure for 5-10 minutes, then kneading with medium pressure for 2-4 minutes, and finally kneading with air pressure for 5-10 minutes.

8. The method for processing fresh green tea according to claim 1, characterized in that: The method of changing temperature and short-time stir-frying in step 6 is: 6.1) Dry the tea leaves after withering for 3-4 minutes at a hot air temperature of 90-110°C and a leaf thickness of 2-3 cm; 6.2) Adjust the hot air temperature to 85-95°C and stir-fry the tea leaves for 4-5 minutes.

9. The method for processing fresh green tea according to claim 1, characterized in that: In step seven, the low-temperature humidity-controlled cooling treatment conditions are: the ambient temperature is 10-15°C, the relative humidity of the environment is controlled to be 60-65% by adding water vapor produced by the withering, the tea leaves are spread to a thickness of 2-3 cm, and the drying time is 10-20 minutes.

10. The method for processing fresh green tea according to claim 1, characterized in that: In step eight, the content of the low humidity temperature change fire is: 8.1) Dry the tea leaves after the second cooling for 10 to 12 minutes at an ambient humidity of about 30% and a hot air temperature of 85 to 90°C; 8.2) Adjust the hot air temperature to 75-85°C and dry for 15-18 minutes.

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